John Charles Frémont (1813-90) was an American explorer, soldier, and politician, born in Savannah, Ga. After serving briefly as teacher of mathematics and engineering in the U.S. Navy, he accepted a post as civil engineer in the Army; in 1838 he was commissioned as second lieutenant of topographical engineers. He gained early fame for his western explorations; in 1842 he made an expedition to southern Wyoming, and in 1843—44 he went to the tidewater of the Columbia and thence to the Sacramento Valley. His reports on California and the Great Salt Lake region turned American attention toward both areas at a time when "manifest destiny" was guiding policy in the direction of national expansion. His third expedition (1845-47) led him to California, in whose conquest he unquestionably wished to have a part. By February, 1846, he had centered his men at San Jose, in the heart of California. The Mexican authorities ordered him to leave the country, but he refused, playing for time. He knew that war between the United States and Mexico was expected. He moved north to Klamath Lake, and then to Sutter's Fort where he encouraged the discontented American settlers in the Sacramento Valley to revolt. News of the outbreak of war reached him in July, 1846, and from then on he actively supported Commanders Robert Stockton and John Sloat in the conquest of California. At the close of the war in 1848, Stockton commissioned him civil governor of California, but Fremont was soon ousted in the bitter quarrel between Stockton and Gen. Philip Kearny over lines of authority in the new territory. As a result, Fremont was court-martialed and dismissed from the service, but President Polk remitted the sentence, allowing him to resign.
